2.2. Results of Summer Shading Simulation Profiles

The results from computer building simulations for the summer shading profiles are analyzed and assessed with the same procedure as for winter. The optimum fenestration profile for summer as defined below is taken as the basis in these series of combinations.

a) Optimized Fenestration Shading Strategy for Summer

The optimised fenestration strategy for summer, derived in previous work [1], is outlined as having all glazed area shaded during the day time to obtain minimum solar gains and hence comfort indoor conditions ranging between 23.3 — 25.4 degrees Celsius (Table 1, 1.4).

b) Half Area of South window Shutters Unshaded

When half of the south window area (17.5m2) is left unshaded during summer days the indoor temperature increases by 0.1 to 0.6 degrees Centigrade (Table 2, 1.3). The small temperature rise seems out of proportion with the large extent of glazing area left unshaded; this is attributed to: Orientation — South orientated windows have no direct solar insolation in the summer.

Design-The optimised design of overhangs and extended vertical walls for south glazing, derived and employed at an earlier stage of the study on “Shading” [1] i. e. shade the solar aperture from the high summer sun while permitting rays from the low winter sun; the optimised design does not leave much space for any further improvement for sun control.

The temperature rise which appears in the current simulation is attributed to the decrease of thermal resistance of windows due to the absence of shutters.

c) All South Window Area Unshaded

When all south window shutters are left unshaded during summer the indoor temperature increases

at the same rate as above (0.1 to 0.5 degrees Celsius, Table 2, 1.2 and 1.3). This increase in temperature deviates from the ones succeeded with optimised design by 0.2 to 1.0 degrees Centigrade (Table 2, 1.4 and 1.2). However the indoor temperature continues to range within comfort levels (23.5 to 26.5 degrees Celsius). The maximum temperature rise (1.0 degree Celsius) reached indoors occurs in the early afternoon and evening hours between 14.00-22.00 hours (Tables 2, 1.2 and 1.4).

d) South and West Windows Unshaded

If in addition to south windows the shutters of west windows are left open during summer day the indoor temperature shows a further rise of 0.1 degree Celsius only at certain hours of the day (table 2, 1.1). The small increase is associated with the small West window area (0.50m2).

e) All Windows Shutters Unshaded

A similar rate of increase presented above (0.2 degrees) occurs when the glazed area (3.50m2) of north windows is left unshaded during the summer (Table 2, 1.0 and 1.1). The indoor temperature is maintained within comfort levels (23.8-26.6 Degrees Celsius). Maximum temperature is reached in the afternoon and early evening hours (16.00-20.00 hours). The peak temperature reaches 26.6 degrees.